Hip distraction

ABSTRACT

An apparatus includes a distractor assembly adapted to couple to a leg and capable of providing a distraction load on the leg in both supine and lateral positions of the leg. The assembly is coupled to a surgical table by a ball joint or a universal joint. A method includes coupling a leg to a distractor assembly, positioning the leg in one of a distraction mode and a femoral acetabular impingement mode, and repositioning the leg in the other of the modes without the need for accessing a draped pelvis/thigh region.

TECHNICAL FIELD

This invention relates to hip distraction.

BACKGROUND

To gain access to the hip joint to perform hip arthroscopy, the femoralhead (ball) is pulled out of the acetabulum (socket) in the pelvis.Hospitals typically use a fracture table to put the hip joint undertraction while the patient is in a supine position. Hip distractors areknown that attach to a standard operating table, and that are dedicatedto use with the patient in either a supine position or a lateralposition.

Two methods for hip distraction are Distraction Mode, in which the lowerextremity is put in tension via traction between the foot and pelvis,and Femoral Acetabular Impingement (FAI) Mode, in which there is notraction on the lower extremity and there is a larger range of motionthan the distraction mode. In the FAI Mode, the hip is flexed up between30 to 90 degrees and the knee is flexed approximately 45 degrees. Thescrub nurse holds the knee from falling laterally. Both methods can beperformed using a fracture table with the patient in the supineposition. To move a patient between the two modes, and to move the hipjoint through its range of motion to check for impingement between thefemoral neck and the acetabular rim, the circulator nurse reaches underthe draped foot area to unlock the table.

SUMMARY

According to one aspect, an apparatus includes a distractor assemblyadapted to couple to a leg and capable of providing a distraction loadon the leg in both supine and lateral positions of the leg.

Embodiments of this aspect may include one or more of the followingfeatures. The distractor assembly includes a joint, for example, a balljoint or universal joint, configured to couple the distractor assemblyto a surgical table. The joint is lockable and the mechanism for lockingthe joint is located remote from the joint. The apparatus is configuredsuch that with a patient positioned on the surgical table and coupled tothe distractor, the joint is offset from the patient's hip joint. Theapparatus is entirely supported by a surgical table.

In an illustrated embodiment, the distractor assembly includes adistractor member and a leg mount, for example, a foot mount, coupled tothe distractor member for movement relative to the distractor member byboth sliding and threaded engagement. The leg mount is coupled to thedistractor member by a ball joint. The apparatus includes a foot holdermountable to the distractor assembly and including a support bar thatsupports the lower leg in the lateral and supine positions.

The apparatus further includes a support configured to be fastened to asurgical table, and the distractor assembly includes a joint, forexample, a ball joint or a universal joint, coupling the assembly to thesupport. The support includes two mounts for coupling to the joint andthe distractor assembly is arranged for use with a patient in a supineposition with the joint coupled to a first of the mounts for surgery ona right leg, or to a second of the mounts for surgery on the left leg.

According to another aspect, a method includes coupling a leg to adistractor assembly, positioning the leg in one of a distraction modeand a femoral acetabular impingement mode, and repositioning the leg inthe other of the modes without the need for accessing a drapedpelvis/thigh region.

According to another aspect, an apparatus includes a distractor memberconfigured for coupling to patient table, and a leg mount coupled to thedistractor for movement relative to the table by both sliding andthreaded engagement.

According to another aspect, an apparatus includes a distractor memberconfigured for coupling to patient table, a ball joint, and a leg mountcoupled to the distractor member by the ball joint. The apparatus isconfigured such that relative movement between the foot mount and thetable applies a distraction load to a patient. Embodiments of thisaspect may include that the apparatus is configured to be entirelysupported by a surgical table.

According to another aspect, an apparatus includes a distractor assemblyconfigured to apply a distraction load to a patient including a balljoint or a universal joint for coupling the assembly to a surgicaltable.

Embodiments of this aspect may include that the joint is lockable, andthat the apparatus is configured such that with a patient positioned onthe surgical table and coupled to the distractor assembly, the joint isoffset from the patient's hip joint.

According to another aspect, an apparatus includes a foot holder for useduring surgery having a support bar configured and arranged to support apatient's lower leg.

According to another aspect, an apparatus includes a distractor member,a support configured to be fastened to a surgical table, and a jointcoupling the distractor member to the support. The support includes atleast two mounts for coupling to the joint.

According to another aspect, a method includes coupling a distractormember to a patient's leg, and dislocating the patient's hip by applyingan adduction force to the patient's leg.

According to another aspect, a method includes coupling a distractormember to a patient's leg, and applying a distraction force with thedistractor member to the patient's leg through a bent knee.

According to another aspect, an apparatus includes means for providing adistraction load on a leg in both supine and lateral positions of theleg.

According to another aspect, an apparatus includes means forrepositioning a leg between a distraction mode and a femoral acetabularimpingement mode without the need for accessing a draped pelvis/thighregion.

Advantages of the apparatus and method may include ease of positioningthroughout the large range of motion required in FAI Mode, ease ofrepositioning between Distraction and FAI Modes, a single system thatallows for both supine and lateral positioning, freeing the scrub nursefrom holding the knee from falling laterally in FAI Mode, and lessexpensive than a fracture table.

The details of one or more embodiments of the invention are set forth inthe accompanying drawings and the description below. Other features,objects, and advantages of the invention will be apparent from thedescription and drawings, and from the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 illustrates a distraction assembly arranged for use in aDistraction Mode with the patient in a supine position.

FIG. 2 illustrates the distraction assembly arranged for use in aDistraction Mode with the patient in a lateral position.

FIG. 3 illustrates the distraction assembly arranged for use in a FAIMode with the patient in a supine position.

FIG. 4 illustrates the distraction assembly arranged for use in a FAIMode with the patient in a lateral position.

FIG. 5 is an isometric view of the distraction assembly and a footholder attached to the distraction assembly.

FIG. 6 is an isometric view of a ball joint of the distraction assembly.

FIG. 7 is an isometric view of a slider and foot mount of thedistraction assembly.

FIG. 8 shows the foot holder attached to the slider.

FIG. 9 is an illustration of a boot of the foot holder.

FIGS. 10A and 10B are isometric views of a table extension for mountingthe distraction assembly to an operating room table with the patient ina supine position.

FIG. 11 is a top view of the distraction assembly also illustrating anon-operative leg holder for the supine position.

FIG. 12 is an isometric view of a lateral positioning table extensionand pad.

FIG. 13 is a top view of the distraction assembly arranged for lateralpositioning.

FIG. 14 illustrates an alternative embodiment of a hip distractor.

FIG. 15 illustrates another alternative embodiment of a hip distractor.

DETAILED DESCRIPTION

Hip distraction is performed in either the Distraction Mode (FIGS. 1 and2) or Femoral Acetabular Impingement (FAI) Mode (FIGS. 3 and 4) using asystem 10 that can be attached to a standard operating table 12, such asfound in hospitals and surgery centers, and that can accommodate bothsupine (FIGS. 1 and 3) and lateral (FIGS. 2 and 4) positioning of thepatient. The system permits operating room personnel to reposition thepatient between Distraction Mode and FAI Mode without needing to accessthe draped pelvis/thigh region.

Referring to FIG. 5, a distractor assembly 100 includes a distractionmember, for example, a longitudinal spar 102 having a D-shapedcross-section, a lockable ball joint 104 (available from Allen Medicalof Acton, MA and as seen in Allen Medical's Ultrafin stirrup products)attached to the proximal (pelvis) end 106 of the spar, a coupler 108attached to the ball joint 104 for coupling the distractor assembly 100to an operating room table, a slider 110 slidably mounted on the spar102, and a leg mount, for example, foot mount 112, attached to slider110 via a lockable ball joint 114 and a rigid, stationary arm 116. Theball joint 104 can be locked and unlocked by actuating a knob 118located at the distal (foot) end 120 of the spar 102, thus allowing forthe assembly to be unlocked and repositioned without need to access thedraped pelvis/thigh region.

The ball joint 104 and the coupler 108, as shown in FIG. 6, allows for alarge range of hip motion, providing a full range of motion about thehorizontal axis, and about 80 degrees of motion in the horizontal plane.The coupler 108 includes a yoke 130 that receives horizontally extendingside arms 132 of the ball joint 104.

Referring to FIGS. 5 and 7, the slider 110 defines a D-shapedlongitudinal through bore 150 that slidably and non-rotationallyreceives the spar 102, and a threaded, lateral through bore 152 thatreceives a locking bolt (not shown), that is tightened to lock theslider 110 to the spar 102. The slider 110 includes handles 154 a, 154 bthat are used by the operating room personnel to slide the sliderrelative to the spar to provide gross distraction of the leg. For finedistraction, the slider 110 includes a base 156 supporting a threadedrod 158 attached to a turn handle 160. The base 156 also slidablysupports a yoke 162 defining a threaded bore 164 through which thethreaded rod 158 is received. By turning the handle 160, the yoke 162,and therefore the foot mount 112 attached to the yoke by the ball joint114 and arm 116, can be moved back and forth relative to the base 156 toapply a desired amount of traction, for example, 25-150 pounds of force,to the leg.

Attached to the foot mount 112 of the assembly 100 is a foot holder 122(FIGS. 5 and 8). The foot holder 122 includes a boot 180, a shin support182, and a support bar 184 that holds the upper tibia aligned with thefoot. The support bar is particularly advantageous during FAI tostabilize the knee from falling laterally thus freeing the scrub nursefrom having to hold the patient's leg in position. Referring also toFIG. 9, boot 180 includes a foot housing 186 with a tightening clasp188, a sole 190, a U-coupling 192 that receives the foot mount 112, andstraps 194 for securing the boot to the foot mount. The foot housing 186has three straps, not shown, that go over the patient's forefoot andclose the foot housing onto the foot.

The support bar 184 has two legs 202 a, 202 b, the ends of which arerespectively received within openings 204 a, 204 b of foot mountcouplers 206 a, 206 b (FIG. 7). The shin support 182 is attached tosupport bar 184 via shin mounts 208. The ball joint 114 and arm 116permit the patient's leg to be finely positioned.

To support the patient's buttocks when the patient is in a supineposition and to attach the distractor assembly 100 to the operating roomtable, a table extension 220 (FIGS. 1 and 10A) is employed. The tableextension 220 includes a frame 222 with a cross bar 224, an angled strut226, a Y-yoke 228, a vertical strut 230, and a platform 232. Extendingfrom the cross bar 224 are two arms 234 a, 234 b that are used to attachthe table extension to the operating room table 12 using rail clamps 14.The coupler 108 of the distractor assembly 100 plugs into one of a pairof female sockets 236 a, 236 b defined in Y-yoke 228 and is secured inplace by a threaded locking knob (not shown). Since the ball joint 104does not provide a large enough range of motion in the horizontal planeto accommodate surgery on both the right and left hips, socket 236 a isused for surgery on the right hip, and socket 236 b is used for surgeryon the left hip, with the ball joint 104 providing the additional rangeof motion in the horizontal plane required for fine position of the leg.

The platform 232 is x-ray translucent and defines through holes 240 a,240 b for receiving a post 242 (FIG. 1). The post 242 is received over arespective plug 244 a, 244 b of Y-yoke 228, and a peroneal pad 244(FIG. 1) slips over the post 242. The post and pad provide therestraining force against the pelvis when the distraction force isapplied to the leg. Through hole 240 a is used for surgery on the righthip, and through hole 240 b is used for surgery on the left hip. Asshown in FIG. 10B, a pad 246 is attached to the platform 232. The paddefines a cut-out 248 permitting access to holes 240 a, 240 b.

Referring to FIGS. 10A and 11, a non-operative leg holder assembly 260is secured within the respective opposite socket 236 a, 236 b from thatin which distractor assembly 100 is secured. Assembly 260 includes aspar 262 to which a foot mount 264 is slidably attached via a lockableslider 266 (FIG. 1). Attached to foot mount 264 is a boot 268 throughwhich mild traction, for example, about 20 pounds can be applied to thenon-operative leg.

To position the patient in the supine position for the Distraction Mode(FIG. 1), operating room personnel lower the operating room table's footsection 16 to the vertical position, clamp the table extension 220 tothe side rails 18 of the table, and connect the distractor assembly 100and leg holder 260 to the table extension. A patient transfer board (notshown) can be attached to the table extension to provide interim supportto the legs while the feet are strapped into the boots 180, 268.

The operating room personnel then place the patient on the table,anaesthetize the patient, and attach the peroneal post and pad to thetable extension. The patient is then brought down the table firmlyagainst the peroneal pad, and the feet are wrapped in disposable foambooties (not shown) and strapped into the boots. The well leg is putunder mild traction and the foot allowed to pivot into it's neutralposition. The operating room personnel remove the patient transfer boardand put the operative leg under initial traction by sliding the carriage110 along the spar 102 until mild traction, for example, about 20 to 50pounds, is achieved. The sliding carriage is then clamped to the spar.Further traction is achieved via the mechanical advantage of thethreaded screw 158 between the carriage and boot. This distracts the hipvia traction through the ankle and knee joints. The foot can be lockedin any orientation (flexion or rotation) via the ball joint 114 betweenthe boot and the threaded screw.

The surgeon then checks the distraction with fluoroscopy, places a drapeover the patient, including covering the pelvis/thigh region of thepatient, and places portals through the patient's skin leading to thehip joint under fluoroscopy control. As soon as the first portal iscreated the vacuum seal between the femoral head and acetabulum isbroken and the joint distracts further. This can be aided by injectingfluid into the joint.

To move the patient from Distraction Mode to FAI Mode (FIG. 3), theoperating room personnel reduce the traction force by turning thethreaded screw 158 until no force is on the joint, unlock the ball joint104, and lift the femur into flexion by raising the spar 102. Since thecenter of rotation of the spar, i.e., the ball joint 104, is locatedbelow the hip joint of the patient, the knee flexes as the spar israised. The natural tendency of the knee to fall laterally is limited bythe boot's lateral support bar 202 a, 202 b thus freeing the scrub nurseto help the surgeon.

Referring to FIGS. 12 and 13, for lateral positioning of the patient,the system 10 includes a “U” shaped peroneal bar 280 supporting a pad282. The bar 280 has a socket 284 for receiving the coupler 108 (FIG. 5)of the distractor assembly 100, and the pad 282 defines a cut-out 286for accessing socket 284. Bar 280 is attached to the side rails 18 ofthe operating room table 12 using clamps 14.

To position the patient in the lateral position for the Distraction Mode(FIG. 2), with the operating room table's foot section 16 up, theanaesthetized patient is rolled onto their side, the operating roompersonnel clamp the bar 280 to the side rails 18 with the pad 282positioned between the patient's legs. To obtain lateral distraction,the operating room personnel raise the bar 280 by rotating the barwithin the clamps 14 and lock the clamps. The distractor assembly 100 isthen attached to the bar 280 and the operative leg wrapped in adisposable foam bootie (not shown) and strapped into the boot. Asdiscussed above, gross distraction is achieved by moving the carriage110 followed by fine distraction using the threaded screw 158. The bootcan be positioned in any combination of flexion or rotation. There is noneed for a non-operative leg holder as the non-operative leg issupported by the table's foot section 16.

To move between the Distraction Mode (FIG. 2) and FAI Mode (FIG. 4), thespar 102 is pivoted laterally about the ball joint 104. Since the centerof rotation of the spar 102, i.e., the ball joint 104, is located distalto the hip joint of the patient, the knee flexes as the spar is movedlaterally. The natural tendency of the knee to fall towards the floor islimited by the boot's lateral support bar 202 a, 202 b, thus freeing thescrub nurse to help the surgeon.

A number of embodiments of the invention have been described.Nevertheless, it will be understood that various modifications may bemade without departing from the spirit and scope of the invention. Forexample, the distractor assembly can include a tensiometer to providethe surgeon with the distraction force. The slide and spar can be otherthan D-shaped, though preferably the slide and spar are configured suchthat the slide can slide along the spar without rotating. The ball joint104 can be replaced with a two axis universal joint 104 a (FIG. 13).Rather than locating screw thread 158 at slider 110, fine adjustment canbe provided by a screw thread located, for example, between the ball 104and the spar 102.

In an alternative configuration shown in FIG. 14, hip distraction isachieved via a pivoting action. Rather than using only axial force todislocate the hip joint, a lever that pivots along the thigh translate asmall foot adduction (movement towards the body centerline) into a largelateral hip distraction force. With a pivot 301 closer to the hip jointthan to the foot end of a spar 310, a simple lever is created. Theoperative foot is held to the spar 310 by a boot assembly 320. Thus,when a small adduction force F₁ is applied to the spar 310 near the footregion, the mechanical advantage provided by the lever creates a largerlateral force at the hip joint. A peroneal pad 344 pushes laterallyagainst the upper femur moving the femoral head of the hip joint. Inaddition to this lateral force, an axial force F₂ is imparted on the hipjoint via traction through the boot assembly 320. This force can beachieved though turning of a crank 360 which is rotationally connectedto a threaded rod 380. The boot assembly 320 is threaded to rod 380 butis limited from rotating by spar 310, thus boot assembly 320 movesaxially when the crank 360 is turned. The peroneal pad 344 also providesa reaction force against the pelvis.

Referring to FIG. 15, distraction can be achieved through a bent kneeproviding a more compact distractor. With the operative leg bentapproximately 90 degrees at the knee, the distraction force can beexerted at the knee. In addition, the reactive force that is bornethrough the non-operative leg can be reacted at the knee rather thanthrough the ankle. Bent knee distraction of the operative leg is carriedout by transmitting a distraction force to the upper tibia via a strap430. The distraction force is transmitted through the knee to thefemoral head. A peroneal pad 444 is connected to the surgical table andreacts the distraction force by pushing against the pelvis. Atelescoping spar assembly 400 includes a bar 420, which is connected toa tube 410 by a slidable, lockable mechanism, such as a one-wayratchetting pawl.

When distraction is pulled on the operative leg, the pelvis tends torotate around a vertical axis “Z” created by the peroneal pad. In orderto minimize this pelvic rotation, a bent knee counter traction force isimparted upon the non-operative leg by a support 440. This force can betransmitted to the upper tibia via surface 450 which is then transmittedthrough the knee to the femoral head and pelvis. The support 440 can befixed to the surgical table or it can telescope like spar assembly 400.If support 440 is fixed then the patient is moved proximally to createthe counter traction force.

Accordingly, other embodiments are within the scope of the followingclaims.

1. An apparatus, comprising: a distractor assembly adapted to couple toa leg and capable of providing a distraction load on the leg in bothsupine and lateral positions of the leg, the distractor assemblyincluding a single actuator configured to be manipulated to controlmovement of the distractor assembly about multiple axes; side railconnectors coupled to the distractor assembly, the side rail connectorsconfigured to attach to side rails of a surgical table; and a footholder mountable to the distractor assembly and including a support barconfigured to extend along a patient's upper tibia.
 2. The apparatus ofclaim 1 wherein the distractor assembly comprises a joint andmanipulation of the single actuator controls the joint.
 3. The apparatusof claim 2 wherein the joint comprises a ball joint.
 4. The apparatus ofclaim 2, wherein the actuator is located remote from the joint.
 5. Theapparatus of claim 2 wherein the joint comprises a universal joint. 6.The apparatus of claim 2 configured such that with a patient positionedon the surgical table and coupled to the distractor assembly, the jointis offset from the patient's hip joint.
 7. The apparatus of claim 2wherein manipulation of the single actuator locks the joint.
 8. Theapparatus of claim 2 wherein manipulation of the single actuator unlocksthe joint.
 9. The apparatus of claim 2 wherein manipulation of thesingle actuator locks and unlocks the joint.
 10. The apparatus of claim1 wherein the distractor assembly comprises a distractor member and aleg mount coupled to the distractor member for movement relative to thedistractor member by both sliding and threaded engagement.
 11. Theapparatus of claim 10 further comprising a ball joint coupling the legmount to the distractor member.
 12. The apparatus of claim 11 furthercomprising, a ball joint located between the leg mount and the threadedengagement.
 13. The apparatus of claim 10 wherein the leg mountcomprises a foot mount.
 14. The apparatus of claim 10 wherein, the legmount is movable over a majority of an entire length of the distractormember.
 15. The apparatus of claim 1 further comprising: a supportcoupling the distractor assembly to the side rail connectors, and thedistractor assembly includes a joint coupling the distractor assembly tothe support, wherein the support includes two mounts for coupling to thejoint.
 16. The apparatus of claim 15 wherein the distractor assembly isarranged for use with a patient in a supine position with the jointcoupled to a first of the mounts for surgery on a right leg, or to asecond of the mounts for surgery on the left leg.
 17. The apparatus ofclaim 15 wherein the joint comprises a ball joint.
 18. The apparatus ofclaim 15 wherein the joint comprises a universal joint.
 19. Theapparatus of claim 15, wherein the support includes: a crossbarconnecting the side rail connectors to each other; and a frame attachedto the cross bar, wherein the two mounts for coupling to the joint areattached to the frame.
 20. The apparatus of claim 1 wherein, thedistractor assembly includes a ball joint; and the apparatus furthercomprises a support for attaching to the surgical table, the support forcoupling the surgical table to the distractor assembly through the balljoint, wherein the support includes the side rail connectors.
 21. Theapparatus of claim 20 wherein the ball joint is lockable.
 22. Theapparatus of claim 20 configured such that with a patient positioned onthe surgical table and coupled to the distractor assembly, the balljoint is offset from the patient's hip joint.
 23. The apparatus of claim1 wherein the foot holder includes a foot housing configured to beattached to a plate of a distractor assembly.
 24. The apparatus of claim23, wherein the foot housing includes toe and heel couplers.
 25. Theapparatus of claim 24, wherein the couplers comprise a u-coupling and astrap.
 26. The apparatus of claim 1 wherein the distractor assemblycomprises: a distractor member, a threaded engagement coupled to thedistractor member, a ball joint coupled to the threaded engagement, anda leg mount coupled to the distractor member by the ball joint, the balljoint located between the leg mount and the threaded engagement, theapparatus configured such that relative movement between the leg mountand the table applies a distraction load to a patient.
 27. The apparatusof claim 26, wherein with the side rail connectors coupled to thepatient table, the apparatus is configured to be entirely supported bythe patient table.
 28. The apparatus of claim 1, wherein with the siderail connectors coupled to the surgical table, the apparatus isconfigured to be entirely supported by the surgical table.
 29. Theapparatus of claim 1 wherein the support bar is configured to supportthe upper tibia in the supine position.
 30. The apparatus of claim 1wherein, the distractor assembly includes a universal joint; and theapparatus further comprises a support for attaching to the surgicaltable, the support for coupling the surgical table to the distractorassembly through the universal joint, wherein the support includes theside rail connectors.
 31. The apparatus of claim 1 wherein the actuatoris located outside of a draped pelvis/thigh region.
 32. The apparatus ofclaim 1 wherein the distractor assembly has a proximal end and a distalend; a joint located at the proximal end of the distractor assembly; anda mechanism for locking the joint located at the distal end of thedistractor assembly.
 33. The apparatus of claim 1 further comprising: asupport configured to attach to side rails of a patient table, thesupport extending the patient table length to support a patient in asupine position, and the support including at least one mount forcoupling a distractor assembly to the support.
 34. The apparatus ofclaim 1 further comprising: a first support including the side railconnectors and a coupler for mounting the distractor assembly thereto toprovide a distraction load on the leg in a supine position of the leg;and a second support including the side rail connectors and a couplerfor mounting the distractor assembly thereto to provide a distractionload on the leg in a lateral position of the leg, the second supportbeing different from the first support.
 35. The apparatus of claim 1,further comprising a table extension attachable to the side rails andthe distractor assembly, wherein the side rails are detachably coupledto the distractor assembly through the table extension.
 36. Anapparatus, comprising: a leg support for use during surgery including asupport bar configured to extend along a patient's upper tibia, thesupport bar having two terminal regions configured to mate to adistractor assembly and a shin support configured to laterally support apatient's lower leg.
 37. An apparatus, comprising: a bar configured tobe fastened to side rails of a surgical table, the bar including asocket for coupling a distractor member to the bar; and a pad connectedto the bar and including a cut-out defined in the pad through which thesocket is accessible for coupling the distractor member to the bar. 38.An apparatus, comprising: a distractor assembly adapted to couple to aleg and capable of providing a distraction load on the leg in bothsupine and lateral positions of the leg, the distractor assemblyincluding a single actuator configured to be manipulated to controlmovement of the distractor assembly about multiple axes; side railconnectors coupled to the distractor assembly, the side rail connectorsconfigured to attach to side rails of a surgical table; and a tableextension attachable to the side rails and the distractor assembly,wherein the side rails are detachably coupled to the distractor assemblythrough the table extension.